A human machine interface (HMI) may allow a user to interact with a system in order to, for example, control and assess the state of the system. The system may be a machine, a device, and so on. Control of the system's state may be accommodated by input provisions (e.g., a slider control, input keypad, pushbutton, tuning knob, etc.) provided by the HMI and assessment of the system's state may be accommodated by output provisions (e.g., a display, indicator lamp, etc.) provided by the HMI.
For example, an HMI used to control and assess the state of a radio device may include a tuning knob, several pushbuttons, volume and tone controls, and a display. The tuning knob, pushbuttons, and volume and tone controls may be input provisions provided by the HMI that are configured to control various states associated with the radio device. For example, the tuning knob may be configured to control the operating frequency of the radio device, the pushbuttons may be used to control the radio device's mode of operation (e.g., AM, FM, etc.) and powering the radio device on and off, and the volume and tone controls may be configured to control the sound produced by the radio device (e.g., set volume level, set tone level, etc.). The display may be an output provision provided by the HMI that is configured to provide an assessment of various states associated with the radio device. For example, the display may indicate a mode the radio is operating in (e.g., AM, FM, etc.), whether the device is powered on or off, the volume and tone levels the radio device is set to, the radio's operating frequency, and so on.